A Comparison of Pleistocene Gastropod Distribution in Both Open Shore and Lagoon at Ash Shaibah South Jeddah, Western Saudi Arabia

International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075,Volume-8, Issue-7C2, May 2019

Abdu M. Almassari, Mohammed Gameil

ABSTRACT--- An exposed succession of raised beaches at the El-Sorogy, et al. (2014) studied two terraces of Late lagoon (5.5m) and the open shore (4.5m), at Ash Shu'aybah area, Pleistocene raised beaches in Rabigh area; It has a sequence 80 Km south of Jeddah City was studied from the Paleontologic of vertical coral reef layers. They identified 35 species of point of view. The focus was carried out on gastropods collected gastropods and 16 species of bivalves from the sequence. from two sites to study their diversity and abundance. The studied raised beach at the lagoon is divided into four distinct layers: They conclude that the fossils similarity between this study dolomitic algal limestone layer (1m); calcareous mudstone layer area and what is currently living in Indo-Pacific and the (2.5m); argillaceous limestone layer (1m); calcareous sandstone Mediterranean Atlantic. About 78% of the fossils have a layer (1m). The open shore raised beach is divided into four range from Pleistocene to Holocene. distinct layers: dolomitic limestone layer (2m decreasing Bantan et al. (2015), studied the lithology, fauna, and northward to 1m); limestone layer (1m increasing northward to environmental conditions of the Pleistocene raised beaches 2m); argillaceous limestone layer (1m); calcareous sandstone layer (0.5m). The calcareous sandstone layer has high diversity of the Jeddah coastal plain. They concluded that the coastal and abundance of gastropods. The study led to the identification plain of Jeddah consists of two featured strata. The lower of 80 gastropod species belonging to 58 genera, 29 families and 7 part is white limestone bed rich in corals (Porites sp., faviids orders. The succession at the lagoon has more species (76 sp.) and foraminifers assemblage (Amphistegina sp., species) than the succession at the open shore (27 species), some Neorotalia calcar). These species indicate that the species are common between the two sites. This is due to the sedimentation in a high-energy, open shore environment difference in energy (currents and waves) and substrate type. The species Conus auricomus is recorded in the Red Sea for the first such as reef crest and fore reef, between 5–10 meters. The time. upper layer is calcareous clay bed is rich in molluscs, Index Terms - Pleistocene, Macrofossils, Gastropods, Ash echinoids, branching corals, and the benthic foraminifera Sha'ibah, MIS 5e, Lagoon, Open shore, Conus auricomus sp., (Elphidium striatopunctatum, Agglutinella robusta, Varidentella neostriatula) suggesting sedimentation in back- I. INTRODUCTION reef, lagoonal environments. The top of the calcareous clay A. Abbreviation: layer is truncated, but in some area, it was covered by fluvial sediments, which indicates a rapid regression in sea-level at Kyr: thousand years; BP: Before Present; Ma: million the end of MIS 5e. years; Km: Kilometer; m: meter; mm: millimeter; L1: According to Manaa et al., (2016) the Late Pleistocene Location 1; L2: Location 2; U/Th: Uranium-thorium dating; raised beaches has 5 km wide flat outcrops, along with the sp.: species; MIS: Marine Isotope Stages. Saudi Arabia coast. The consistent elevation of these raised B. Previous Works: beaches is due to tectonic stability of the sea coast at the In western Saudi Arabia particularly around Jeddah city, southern and central Saudi Arabia for at least 125 kyr BP, the marine terraces form a flat platform that is raised 3-6 m and the coral reef terraces are consistent with the Marine above sea level. It is poorly exposed because of a covering Isotope Stages (MIS 5e), which reached a peak of 6–9 m of fossil-rich sand, sabkha and alluvial deposits (Moore and above present sea level. Al Rehaili. 1989). Recently, Abu Zeid and Bantan (2018), studied the Manaa et al., (2011), carried out a U/Th dating of the Red Pleistocene raised reefal limestone south Sharm Obhur, Sea, they concluded that average age of coral ranges from north of Jeddah city. They recorded 90 species of 119.9 to 122 kyr BP, it is within the age of the last gastropods. They divided the section into two parts. The interglacial (MIS 5e at 128–116 kyr BP) when coastline was lower part is white limestone, and no specific species prevail 6 m higher than now. in this layer. The upper part is calcareous mud rich in gastropods, that match to the last Marine Isotope Stages (MIS 5e). Between the two strata an erosional surface indicating regression of sea level through the deposition of Revised Manuscript Received on May 29, 2019. the interval MIS 5e. Abdu M. Almassari, Department of Petroleum Geology and Sedimentology, Faculty of Earth Sciences, King Abdulaziz University, Jeddah, Saudi Arabia. Saudi Geological Survey, Jeddah, Saudi Arabia.(E- mail: [email protected]) Prof. Mohammed Gameil, Department of Petroleum Geology and Sedimentology, Faculty of Earth Sciences, King Abdulaziz University, Jeddah, Saudi Arabia. (E-mail: [email protected])

Published By: Blue Eyes Intelligence Engineering Retrieval Number: G10010587C219/19©BEIESP 1 & Sciences Publication International Conference on Multidisciplinary Perspectives in Engineering & Technology (ICMPET-19) |24th -25th May, 2019 | KITS, Markapur, Andhra Pradesh, India

white color on the weathered surface, yellowish gray on the fresh surface, including small borings, Echinoid spines, and colonial corals at the top. The second layer is fine grained calcareous mudstone (thickness: 2.5 m) overlying the hard limestone, it is dark brown, rich in coral fragments and dominated by Fungia sp. and other colonial corals, bivalves and large gastropods at the top. The third layer is hard argillaceous limestone (1 m), it is grayish white, composed mainly of thinly branching Acropora sp., highly bored and cavernous, it is rich in bivalves dominated by Tridacna sp., Spondylus sp., and Oysters, the gastropods are found at the top. The fourth layer is calcareous sandstone (1 m), it is brownish gray, very rich in gastropods and thinly branching

corals (fig. 2). Figure 1: Map showing the location of the study area. The second section of the open shore at Ash Shu'aybah area (L2), consists mainly of four distinct layers with a Many studies conducted the sedimentological, thickness about 4.5 meters, it was measured at the geomorphological and mineralogical aspects of raised coordinate (20° 48' 41" N and 39° 25' 35" E). The section is beaches (Nesteroff 1960; Dawood et al. 2013). composed of (from bottom to top) hard dolomitic limestone, The main aim of this work is to study Pleistocene yellowish white color in the fresh surface, dark gray color in gastropod distribution in two different localities, and the weather surface. It contains many echinoid spines and effect of environments on diversity and abundance of poorly preserved casts and molds of gastropods and species, in Ash Sha'ibah al Masdūdah (open shore and bivalves. The thickness is 2 meters but decreases northward lagoon), about 80 km south of Jeddah. to 1 meter. The second layer is fine grained limestone dark brown color in the weathered surface, grayish white color in II. STUDY AREA the fresh surface with algae, bivalves and large gastropods at The area of the study is located south of border guard- the top. The thickness is 1 meter but increases northward to center of Ash Sha'ibah al Masdūdah, 80 Km south of Jeddah 2 meters. The third layer is hard argillaceous limestone with City. Two sites were selected representing two different thickness 1 m; it is white in color, cavernous, and rich in environments lagoon has coordinates (20° 48' 55" N and 39° poorly preserved fossils of gastropods and branching corals. 25' 53" E) and, open shore has coordinates (20° 48' 41" N The thickness is 1 meter. The fourth layer is calcareous and 39° 25' 35" E), the distance between the two sites is sandstone (0.5 m); it is brownish gray in color, very rich in about 700 meters (Fig. 1). The area is composed of a gastropods and colonial corals (fig. 3). carbonate platform that rises about 5.5 meters above the present shoreline. The thickness of the raised beaches varies between the two locations.

III. MATERIALS AND METHODS Several field trips were carried out in the study area. About 535 gastropod specimens were collected from the exposed surface. The collected gastropods were washed and cleaned by water; they are later dried and studied from the taxonomic view point.

IV. RESULTS AND DISCUSSION A. Lithology and Stratigraphy: Previous studies dealt with the age dating of the coral reef terraces at the eastern part of Red Sea using the U/Th series, indicated an age of 140–110 kyr BP according to Plaziat et al. (2008); 235–128 kyr BP according to Dawood et al. (2013); 125–121 kyr BP according to Bantan et al. (2015); and 122–119 kyr BP according to Manaa et al. (2016). These ages belong to the last interglacial MIS 5e (Late Pleistocene). The studied section at the lagoon of Ash Sha'ibah al Figure 2: Stratigraphic column of location 1(lagoon). Masdūdah (L1), consists mainly of four distinct layers with thickness about 5.5 meters, it is about 75 meters far from the current beach, it was measured at the coordinate (20° 48' 55" N and 39° 25' 53" E). The measured section is composed of (from bottom to top) hard algal limestone (1 m), it is grayish

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International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075,Volume-8, Issue-7C2, May 2019

concinnum; Ranularia exilis; Euplica turturina; Pyrene splendidula; Fasciolaria scalarina; Latirus polygonus; Fusinus leptorhynchus; Fusinus rostratus; Nassarius arcularia; Nassarius clarus; Tritia nitida; Sycostoma bulbus; Volema pyrum; Pollia fumosa; Conus auricomus; Conus flavidus; Conus pennaceus; Conus terebra; Lophiotoma abbreviate; Nebularia pellisserpentis; Mitra turgida; Strigatella aurantia; Strigatella coronata; Nassa francolina; Bulla ampulla; Aliculastrum cylindricum; Nerita histrio; Nerita striata; Neritopsis radula; Haliotis rugosa; Trochus maculatus; Trochus noduliferus; Clanculus pharaonius; Turbo petholatus. Rhinoclavis aspera; Mammilla melanostoma; L2 Nerita yoldii; Tectus dentatus. Cerithium caeruleum; Rhinoclavis vertagus; Monetaria moneta; Erronea caurica; Mauritia arabica; Canarium mutabile; Conomurex fasciatus; Gibberulus gibberulus; Lambis truncate; Tricornis tricornis; Tibia Figure 3: Stratigraphic column of location 2 (open L1+L2 insulaechorab; Monoplex nicobaricus; Malea shore). pomum; Pleuroploca trapezium; Conus arenatus; Conus vexillum; Terebra subulata; In general, most fossils of the two locations are collected Chicoreus virgineus; Vasum turbinellus; Nerita form of the upper two layers which are composed of albicilla; Nerita textilis; Clanculus puniceus; argillaceous limestone and calcareous sandstone. Also, most Turbo radiatus of the small fossils in L2 are poorly preserved in the form of casts and molds. Table 1: A table showing the distribution of gastropods species in the studied two locations. B. Biodiversity and paleoenvironmental interpretation: The third layer is argillaceous limestone in two locations, In the present study, 535 gastropod specimens were but there is a significant difference in size, number, and collected, 363 specimens are collected from L1 and 172 quality of preservation of fossils. This layer in L1 is rich in specimens from L2. These fossils belong to 4 subclasses, 7 thinly branching Acropora, bivalves dominated by Tridacna orders, 16 superfamilies, 29 families, 58 genera, and 80 with large size, and gastropods. This indicates shallow and species. The species dominated in the two localities are low energy marine environments in warm tropical waters Gibberulus gibberulus albus and Rhinoclavis vertagus. (lagoon environments). The same equivalent layer in L2 23 species are common in the two locations and 53 contains poorly preserved gastropods, bivalves, and in situ species in the L1 only and 4 species in the L2 only (Table dendritic corals. These indicate the shallow open marine 1). environments in warm tropical waters. Corals exist in the two locations, except for the calcareous The top most layer is composed of calcareous sandstone sandstone that is rich in gastropods only. The base of the in the two sites, it is very rich in gastropods, and colonial section is composed of dolomitic limestone containing no corals in L2, but there is a difference in thickness of the gastropods. A few poorly preserved specimens are found in layer. L2 in the form of cast, and mold of gastropods and bivalves The reason for the difference in diversity, abundance, together with many echinoid spines. size, and preservation of fossils between the lagoon The second layer is composed of calcareous mudstone in environment and the open shore environment is due to the L1, dominated by Fungia and other colonial corals but they energy difference between the two localities. change to limestone in L2 with few algae and bivalves. C. Gastropods taxonomy Location Species Cerithium nodulosum; Cerithium scabridum; L1: Indomodulus tectum; Planaxis sulcatus; 1. Genus: Cerithium Monetaria annulus; Naria erosa; Nucleolaria Cerithium nodulosum (Bruguière, 1792) nucleus; Staphylaea limacina; Cypraea Elongated shell, the spire is rapidly ascending; at the L1 pantherine; Palmadusta clandestina; Pustularia dorsal of body whorl marked by spiral lines that appear in bistrinotata; Pustularia globulus; Pustularia aperture and makes it marerubra; Pustularia margarita; Notocochlis distinctive. (Fig. 4 A) gualtieriana; Strombus alatus; Terestrombus

terebellatus; Bursa granularis; Gyrineum

Published By: Blue Eyes Intelligence Engineering Retrieval Number: G10010587C219/19©BEIESP 3 & Sciences Publication International Conference on Multidisciplinary Perspectives in Engineering & Technology (ICMPET-19) |24th -25th May, 2019 | KITS, Markapur, Andhra Pradesh, India

2. Genus: Conus a. Conus auricomus (Hwass in Bruguière, 1792) The shell is a cylindrical shape, has a stain convex spire, and revolving striae at all shell. This species is common in the Indo-Pacific, but this is the first record in the Red Sea. (Fig. 4 B) b. Conus nussatella (Linnaeus, 1758) The shell is closely striated, the striae minutely granular, with many brown spots on the striae. The spire is short. (Fig. 4 C) c. Conus pennaceus (Born, 1778) The shell is conical shape, covered by minute white triangular spots. (Fig. 4 D) 3. Genus: Haliotis Haliotis rugosa (Reeve, 1846) Small oblong shell, convex, has many round holes. (Fig. 5 A)

Figure 5: A Haliotis rugosa (Reeve, 1846) Scale bars 5 mm, B Mitra turgida (Reeve, 1845) Scale bars 5 mm, C Turbo petholatus (Linnaeus, 1758) Scale bars 10 mm, D Rhinoclavis aspera (Linnaeus, 1758) Scale bars 10 mm, E Tectus dentatus (Forskål in Niebuhr, 1775) Scale bars 50 mm.

Figure 4: A Cerithium nodulosum (Bruguière, 1792), B Conus auricomus (Hwass in Bruguière, 1792), C Conus nussatella (Linnaeus, 1758), D Conus pennaceus (Born, 1778). Scale bars 10 mm. 4. Genus: Mitra Mitra turgida (Reeve, 1845) The shape of the shell is ovoid, distended in the middle, has the short spire, many spirally grooved, and three ridges from columella. (Fig. 5 B) 5. Genus: Turbo Turbo petholatus (Linnaeus, 1758) The shell is smooth and solid. Characterized by a circular aperture, which is approximately half the size of the shell. The inner lip is sharp. (Fig. 5 C). L2: Figure 6: A Conus arenatus (Hwass in Bruguière, 1792) 1. Genus: Rhinoclavis Scale bars 20 mm, B Gibberulus gibberulus (Linnaeus, Rhinoclavis aspera (Linnaeus, 1758) 1758) Scale bars 10 mm, C Rhinoclavis vertagus The shell is elongated slender; it has a sharp spire. At the (Linnaeus, 1767) Scale bars 10 mm, D Terebra subulate surfaces shown radial sculpture, axial ridges, and nodules. (Linnaeus, 1767) Scale bars 30 mm, E Vasum turbinellus (Fig. 5 D) (Linnaeus, 1758) Scale bars 20 mm.

International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075,Volume-8, Issue-7C2, May 2019

2. Genus: Gibberulus The most important result of this study was the first Gibberulus gibberulus (Linnaeus, 1758) record of Conus auricomus in the Red Sea; this species is The shell is gibbous, smooth in the frontal, and grooved common only in the Indo-Pacific. in the dorsal. The aperture is scarlet pigment. (Fig. 6 B). ACKNOWLEDGMENT 3. Genus: Tectus I would like to thank Prof. Mohammed Gameil for his Tectus dentatus (Forskål in Niebuhr, 1775) supervision, efforts, observations, and review of this work. I It is large conical turret shape, has rhomboidal aperture would like to thank the head of Petroleum Geology and and rounded protrusions. (Fig. 5 E) Sedimentology Department Dr. Faisal Al-Kahtani for L1+L2: offering facilities to work in the department. Special thanks 1. Genus: Conus to the Saudi Geological Survey for their scientific and administrative facilities to its junior staff to carry out Conus arenatus (Hwass in Bruguière, 1792) postgraduate studies. The shell is a conical shape, covered by minute brown spots. The spire is low and crown at the top. (Fig. 6 A) REFERENCES 2. Genus: Rhinoclavis 1. R. H. Abu-Zied, and R. A. Bantan, “Late Pleistocene Rhinoclavis vertagus (Linnaeus, 1767) gastropods from the raised reefal limestone of Jeddah, Saudi The shell is a fusiform shape. Characterized by axial Arabia: taxonomic and palaeoenvironmental implications,” plaits at the top of whorls, and sharp inner lip. (Fig. 6 C) PalZ, vol. 92, Issue 1, pp.65-86, March 2018. 2. R. A. Bantan, “Morphological features and sedimentological 3. Genus: Terebra aspects of Wadi Al-Kura, north of Jeddah, western coast of Saudi Arabia,” Journal of King Abdulaziz University Marine Terebra subulate (Linnaeus, 1767) Sciences vol. 17, pp 153–165, 2006. The shell is very elongate, well rounded whorls and a 3. R. A. Bantan, R. H. Abu-Zied, and R. A. Haredy, “Lithology, sharp spire with a small aperture, and two rows spots at fauna and environmental conditions of the Late Pleistocene whorls but the body whorls has three rows. (Fig. 6 D) raised reefal limestone of the Jeddah coastal plain, Saudi Arabia,” Arabian Journal of Geosciences Volume 8, Issue 11, 4. Genus: Vasum pp 9887–9904. November 2015. Vasum turbinellus (Linnaeus, 1758) 4. Y.H. Dawood, M.A. Aref, M.H. Mandurah, A. Hakami, and M. Gameil. “Isotope geochemistry of the Miocene and The shell is widely conical such as vase shape with low Quaternary carbonate rocks in Rabigh area, Red Sea coast, spires. The shell has thick and large knobs, appear five plaits Saudi Arabia,” Journal of Asian Earth Sciences 77: 151–162, on the columella. (Fig. 6 E). 2013. 5. A. El-Sorogy, M. Youssef, M. Al-Sabrouty, N. Al-Otaiby, CONCLUSIONS “Facies pattern and molluscan fauna of the Late Pleistocene raised coral reef of Rabigh area, Red Sea coast, Saudi Generally, the studied sections are composed of Arabia,” Indian Journal of Geo-Marine Sciences Vol. 43(8), limestones. It occurs at Ash Shu'aybah, 80 Km southern pp. 1571-1580, August 2014. Jeddah city which raised about 5 m above the current sea 6. A. Manaa, “Late Pleistocene raised coral reefs in the eastern level. Red Sea–Rabigh, Saudi Arabia,” Master of science – Lithologically, the lagoon section is divided into four Research thesis, School of Earth and Environmental Sciences, University of Wollongong, 2011. http://ro.uow.edu.au/theses/ distinct layers: dolomitic algal limestone layer; calcareous 3501 mudstone layer; argillaceous limestone layer; calcareous 7. A.A. Manaa, B.G. Jones, H.V. McGregor, J.-X. Zhao, and sandstone layer. This section is very rich in gastropods D.M. Price. “Dating quaternary raised coral terraces along the which are represented by 76 species. The open shore section Saudi Arabian Red Sea coast,” Marine Geology 374: 59–72, is divided into four distinct layers: dolomitic limestone 2016. layer; limestone layer; argillaceous limestone layer; 8. T.A. Moore, and Al-Rehaili, M.H.A., “Geologic Map of the Makkah Quadrangle,” Sheet 21D, Kingdom of Saudi Arabia. calcareous sandstone layer. This section has rare gastropods Ministry of Petroleum and Mineral Resources, Jeddah, (1989). where 27 species are only identified, compared to the other 9. W.D. Nesteroff, “Age des derniers mouvements du graben de section. 23 species are common in the two locations. la Mer Rouge de´termine´ par la me´thode du C14 appliqueé The different number of species between lagoon (L1) and aux rećifs fossils (Age of the last movements of the Red Sea open shore (L2) is due to the difference in depositional graben determined by the carbon-14 method applied to fossil environments, and the intensity of sea currents and waves. reefs),” Bulletin de la Socie´te´ Geólogique de France 20: 415–418, 1960. These gastropods belong to 4 subclasses, 7 orders, 16 superfamilies, 29 families, 58 genera, and 80 species. The species dominated in the two localities are Gibberulus gibberulus albus and Rhinoclavis vertagus. The calcareous sandstone layer (top layer in sections) has higher diversity and abundance of gastropods than the other layers which may be related to the last interglacial marine isotope stage 5e (MIS 5e).